Service providers may have the option to extend credit to customers for provided services with the expectation of payment at the termination of a service period. Alternatively, a service provider may require a customer to pay for services before they are provided. So-called prepaid services may allow a customer to purchase services prior to their provision and usage. Accordingly, a prepaid customer may maintain a positive monetary balance in a prepaid account held with the service provider. Alternatively, the customer may purchase units of service from the service provider for use over a period of time. In the example of a telephone network, a prepaid customer may purchase telephone services in units such as minutes.
The telephone network operator may establish a prepaid account for tracking the usage of any purchased minutes. In certain contexts, e.g., business customers and family calling plans, among others, it may be desirable to maintain a prepaid account that allowing multiple users to draw down a single account balance.